Kerala’s Unusual Rain

by Paul Gilster on May 19, 2006

The red rain that fell in the Indian state of Kerala continues to create interest. Are the particles found suspended within it extraterrestrial in nature? The rain first fell on the 25th of July, 2001, but red rain phenomena continued to occur for two months thereafter, although in some cases other colors appeared, and there are reports of colored hailstones. This was no one-shot event. I’ve held off on this story hoping to get further information, but enough readers have asked for details that I’ll go with what we now have.

We know this much: The red color is caused by the mixing of microscopic red particles with the water, the characteristics of which are unusual. As noted by Godfrey Louis and Santhosh Kumar (Mahatma Gandhi University) in their paper on the subject, the particles vary from 4 to 10 microns in size and appear under magnification as red-colored glass beads. Electron microscope work shows them to have “…a fine structure similar to biological cells.”

Kerala's red rain

And although they look something like unicellular organisms, the particles show no nucleus, although dyes reveal ‘…a layered structure after the dye penetration.’ They’re also quite stable over time, showing no decay or discoloration after storage without preservatives for over four years. No trace of RNA or DNA can be found.

Image: Red rain particles under 1000x magnification. The inset shows red rainwater in a 5 ml sample bottle. Credit: Godfrey Louis and Santhosh Kumar.

Moreover, the major elements found in these particles are carbon and oxygen. The amount of material is substantial: With more than 100 reported cases of red rain, the authors surmise that, at minimum, over 50,000 kg of red particles are involved. They rule out particles washed out from rooftops or trees, and find it unlikely that, given the wide dispersion geographically, the particles are pollen or fungal spores. Nor do they believe a serious case can be made that the red rains were caused by desert dust.

A meteoric origin thus cannot be ruled out. From the paper:

The red rain phenomenon first started in Kerala after a meteor airburst event, which occurred on 25th July 2001 near Changanacherry in Kottayam district. This meteor airburst is evidenced by the sonic boom experienced by several people during early morning of that day. The first case of red rain occurred in this area few hours after the airburst event. This points to a possible link between the meteor and red rain. If particle clouds are created in the atmosphere by the fragmentation and disintegration of a special kind of fragile cometary meteor that presumably contain a dense collection of red particles, then clouds of such particles can mix with the rain clouds to cause red rain. The atmospheric fragmentation of the fragile cometary meteor can be the reason for the geographical distribution of the red rain cases in an elliptical area of size 450 km by 150 km.

Upshot: The authors argue strongly for an extraterrestrial origin and consider the red rain a possible case of panspermia. The source could be cometary, as has been argued before by Fred Hoyle and Wickramasinghe (in “Comets – A Vehicle for Panspermia, Astrophysics and Space Science 268, pp. 333-341). The paper is “The Red Rain Phenomenon of Kerala and Its Possible Extraterrestrial Origin,” accepted for publication in Astrophysics and Space Science, and available here. Thanks to Luke Schubert for the pointer to this one.

Centauri Dreams‘ take: The authors seem too quick to dismiss terrestrial alternatives. That the particles in Kerala’s unusual rains deserve further study is obvious. What isn’t clear is why more conventional explanations are getting such short shrift. If Kerala is a case of panspermia caught in the act, surely the best way to demonstrate it is through a series of studies that convincingly discount the pollen and dust hypotheses, while running additional tests on those odd, cell-like structures. Drawing potentially breakthrough conclusions from evidence that has yet to be fully analyzed is questionable science.

pfdietz May 19, 2006 at 11:47

Have they analyzed oxygen isotopes? If terrestrial, they will lie on the ‘SMOW’ line, if ET, probably not.

Administrator May 19, 2006 at 13:39

To my knowledge this has not been done, though I hear that the authors have continued their work on the particles, and perhaps they have something more that hasn’t yet been published.

ozne May 19, 2006 at 17:04

If indeed the link between the red rains of Kerala and a
meteorite can be proven, then it has been known for a while
that organic compounds in meteorites, when interacting with
water, can form vesicles that look like cells.
For example, this is mentioned with regard to the Murchison
meteorite in this NASA page :

This is also been done with simulated interstellar ice as
mentioned in this interview with a co-investigator for the
Stardust mission :

I seem to remember (but I can’t find references to this)
that vesicles obtained with similar processes can be made
to “replicate” under certain circumstances.

Both links above have pictures of the vescicles.


Administrator May 19, 2006 at 17:54

Enzo, this is fascinating. I hadn’t heard about this at all — thanks for the links!

ozne May 19, 2006 at 19:36

New Scientist (NS) published about Kerala in March:
I got a letter published which is basically a copy of my posting here.
That was my best guess PROVIDED THAT the link between a meteorite
and the rain could be proven.

NS has also followed up with some samples sent to other labs and,
from this other article, DNA appears to have been found :

Neither articles are public, but you can read the start of them and
you can search their site for more on it.


sdtimme June 15, 2006 at 2:19

Preprint submitted to astrophysics e-print archive on December 29, 2003
New biology of red rain extremophiles prove
cometary panspermia
Godfrey Louis & A. Santhosh Kumar
School of Pure and Applied Physics, Mahatma Gandhi University,
Kottayam – 686 560, Kerala, India. (e-mail:
This paper reports the extraordinary biology of the microorganisms from the
mysterious red rain of Kerala, India. These chemosynthetic organisms grow
optimally at an extreme high temperature of 300 degrees C in hydrothermal
conditions and can metabolize inorganic and organic compounds including
hydrocarbons. Stages found in their life cycle show reproduction by a special
multiple fission process and the red cells found in the red rain are identified as the
resting spores of these microbes. While these extreme hyperthermophiles contain
proteins, our study shows the absence of DNA in these organisms, indicating a new
primitive domain of life with alternate thermostable genetics. This new biology
proves our earlier hypothesis that these microbes are of extraterrestrial origin and
also supports our earlier argument that the mysterious red rain of Kerala is due to
the cometary delivery of the red spores into the stratosphere above Kerala.
Keywords: Astrobiology; extremophiles; panspermia; comet; red rain; hyperthermophiles;
last common ancestor; origin of life; fourth domain of life.

DR.SAINUSEEN July 13, 2006 at 4:04

red rain was not due to explosion of meterioles or biocells. it is due to geological phenomena. if you require more details me.

ljk February 7, 2008 at 15:26

Claim of alien cells in rain may fit historical accounts: study

Jan. 22, 2008

Special to World Science

A con­tro­ver­sial the­o­ry, that strange red rains in In­dia six years
ago might have con­tained mi­crobes from out­er space, has­n’t died.

In fact, things might be get­ting even weirder.

A new study sug­gests the claimed con­nec­tion be­tween scar­let
rain and ti­ny ce­les­tial vis­i­tors may be con­sist­ent with his­tor­i­cal
ac­counts link­ing col­ored rain to me­te­or pass­ings. These would
seem to ech­o the In­dia case, in which or­gan­isms are pro­posed
to have fall­en out of a break­ing me­te­or.

“Some of these [past] ac­counts may have been ex­ag­ger­at­ed,”
cau­tioned the new stu­dy’s au­thor in re­port­ing his find­ings,
adding that con­si­der­able prob­lems also dog the alien-cell pro­po­sal.

Yet the his­tor­i­cal anal­y­sis, he con­clud­ed, shows the ques­tion is
“much more com­plex than one might have ex­pect­ed” and “should
be in­ves­t­i­gated with eve­ry sci­en­tif­ic re­source” avail­a­ble.

The stu­dy, by doc­tor­al stu­dent Pat­rick Mc­Caf­ferty of Queen’s
Un­ivers­ity Bel­fast, is pub­lished in the ad­vance on­line edi­tion
of the In­terna­t­ional Jour­nal of As­tro­bi­ol­o­gy.

Full article here:

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